Re: Why is Garmin
Yeah, I did a trawl for a smartwatch-type device, having had one of the generic Chinese fitness band devices fail on sync after about 2 years use, and came away thinking that Garmin was a decent option. I was umming and ahhing about Forerunner735XT or Fenix 3, which are about the same price, (choice basically metal or plastic case) or VivoActive, which looks neat, costs less even if it seems to have jumped up about £50 since Christmas, but has touch screen niggles if used in the wet that don't affect the other two with their physical buttons. Garmin might have iffy customer service according to some reviewers, but their watches work for sports/fitness uses, plus don't have the sync issues with Android 6 that seem to plague some FitBit and TomTom users.
I had considered the TomTom Runner 3 (it has multi-sports modes despite its name), which is good on the GPS/breadcrumb trail side of things, although IIRC didn't do so well on gym-based cycling/running, but it seems they've just bailed from the wearables market. Another brand a triathlete friend of mine uses and has gone back to after trying the TomTom Runner range is Suunto - seems to be a split between them and Garmin for the folk who do du-/tri-athlons, Iron Man, etc., but don't do Apple. HR on the wrist is useful, though most of the 'serious' folk would need the ability to link in HR chest bands, plus bike metrics sensors for speed/cadence.